Constructs & returns a new TAP::Parser::Iterator::Process for the source. Assumes $source->raw contains a reference to the perl script. croaks if the file could not be found.

The command to run is built as follows:

$perl @switches $perl_script @test_args

The perl command to use is determined by "get_perl". The command generated is guaranteed to preserve:

PERL5LIB
PERL5OPT
Taint Mode, if set in the script's shebang

Note: the command generated will not respect any shebang line defined in your Perl script. This is only a problem if you have compiled a custom version of Perl or if you want to use a specific version of Perl for one test and a different version for another, for example: